Sudafed is the proprietary name for a decongestant containing pseudoephedrine. The product has been available for many years and is generally regarded as a safe and effective product that is suitable for OTC (over the counter) sale. However, there is no specific data about its use in pregnancy. Also, it is known to be excreted in breast milk but there is no data on the effects of this on breast fed infants. It is also important to emphasise that there is no evidence to suggest that it might be harmful. To answer your specific question; as a general rule of thumb it is probably best to avoid all oral OTC medication when trying to conceive unless symptoms are very uncomfortable.